Odd gearing to issue

[dfthe1]

I've had some gear niggles for a while -- slow shifting, shifting multiple gears, shifting without me doing anything. Also a loud intermittent cracking noise. Obviously needs indexing and possibly new cables plus some other stuff but haven't found the time to go through it all and sort it out.

Odd thing on my ride today though. Was happily cycling along at around aroUnd 20mph when the cranks suddenly starting spinning freely as though the chain had come off. A few seconds later it was fine, but then kept doing it.

I stopped to look but couldn't see anything obviously wrong. When I went to set off, the cranks turned freely about 270 degrees before the gear 'caught'. Did this a few more times then seems fine for the last 10 miles home.

Any ideas what the problem could be?

 

[ianrauk]

Number 1. Sounds like frayed or damaged cable.
Number 2. Sounds like a freehub problem. The pawls may be sticking open which means that it doesn't engage with the wheel meaning no drive. This could be due to worn components in the freehub or a build up of gunk inside.

Both need to be sorted sooner rather then later. If you can't or don't want to do yourself then it's a bike shop matter.

 

[dfthe1]

Number 1. Sounds like frayed or damaged cable.
Number 2. Sounds like a freehub problem. The pawls may be sticking open which means that it doesn't engage with the wheel meaning no drive. This could be due to worn components in the freehub or a build up of gunk inside.

Both need to be sorted sooner rather then later. If you can't or don't want to do yourself then it's a bike shop matter.

Great -- thanks. Done a bit of reading and it looks like the freehub could be the cause of the cracking sound too. Any thoughts on whether to try to overhaul or just get a new one? Doing either is no problem (apart from finding the time!)

 

[Tim Hall]

Great -- thanks. Done a bit of reading and it looks like the freehub could be the cause of the cracking sound too. Any thoughts on whether to try to overhaul or just get a new one? Doing either is no problem (apart from finding the time!)

Freehubs are generally replaceable rather than fixable (give or take fancy boutique models). Look up which model you have and see how much a new one is before you decide.

 

[si_c]

If the pawls are sticking it may even be as simple as cleaning and relubricating the free hub. Worth a go I'd reckon, if it doesn't work then you can look at getting a new one then.

 

[PeteXXX]

^ what @si_c said..
I had similar a while ago.

 

[Pale Rider]

If the freehub conks out completely - pedals spinning, no drive - before you get around to fixing it, it's worth bouncing the back wheel off the road a few times.

As said, the problem is likely to be pawls not engaging, so the shock of the bouncing can often persuade them to engage at least for long enough to get you home.

 

[dfthe1]

If the freehub conks out completely - pedals spinning, no drive - before you get around to fixing it, it's worth bouncing the back wheel off the road a few times.

I was SO glad of this tip 10 miles from home in this morning's freezing weather. Thank you!

Now where's that chain whip...

 

[screenman]

Great -- thanks. Done a bit of reading and it looks like the freehub could be the cause of the cracking sound too. Any thoughts on whether to try to overhaul or just get a new one? Doing either is no problem (apart from finding the time!)

Get up earlier.

 

[dfthe1]

So...

(@Kumquat -- you will probably find this relevant, too)

I've taken off the cassette to get to the free hub, which seemed to be a standard Shimano type (loose bearings, tell-tale hump in the hub). I've removed the axle and bearings but just can't figure out how to remove the freehub body. A 10mm hex wrench is too small, and I can't actually see any evidence of a hex nut anywhere, or anything else to remove the freehub.

Is it possible the freehub body just isn't removable? It's a Halfords cheapie so no info about the hub or freehub brand.

http://www.halfords.com/cycling/bikes/road-bikes/carrera-crixus-limited-edition-cyclocross-bike-2015

Any ideas?

 

[Tim Hall]

Some are an annoying 11mm.

 

[dfthe1]

Some are an annoying 11mm.

I thought that, but it just looks cylindrical the whole way through. I'll try to find and 11mm wrench and have a go...

Thanks!

 

[oldwheels]

As I remember the allen key goes from the non drive side and not through the freehub bit. Sounds illogical but it a long time since I removed one.

 

[Tim Hall]

As I remember the allen key goes from the non drive side and not through the freehub bit. Sounds illogical but it a long time since I removed one.

Not in my experience.

 

[fossyant]

Non-drive side for non-shimano hubs - access it from there but 11 or 12mm hex.